Pesticidal compositions and methods

ABSTRACT

The present invention provides an environmentally compatible, pesticidal composition and method for the control of insect pests. The composition includes two components. The first component is a chelating agent, a metal complex of a chelating agent, and mixtures thereof, and the second component is preferably a carrier material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.10/657,419, filed on Sep. 8, 2003, entitled “Pesticidal Compositions andMethods,” and further claims priority from U.S. Provisional PatentApplication Ser. No. 60/413,688, filed on Sep. 26, 2002, entitled“Ingestible Pesticidal Composition,” the disclosures of which areexpressly incorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to environmentally safe pesticides, andmore particularly to a pesticidal formulation containing chelatingagents and/or their metal complexes that are effective to control insectpests.

BACKGROUND OF THE INVENTION

In recent years, concerns have been raised about the potential danger ofsynthetic pesticides to humans and other non-target organisms. With thisincreased concern about toxicity and environmental safety, there hasbeen a renewed interest in the use of safer substances, includingnatural active ingredients, for pest control. Chelating agents have along history of human use and are widely used in the food, cosmetic andpharmaceutical industries. One of the best known pharmaceutical uses ofchelating agents is in the treatment of heavy metal poisoning(Remington's Pharmaceutical Sciences). Chelating agents are also usedextensively as stabilizers because they prevent oxidation of susceptiblecompounds by sequestering metal ions, which can catalyze degradationreactions.

Metal chelates are reported in the literature as control agents formolluscs (slugs and snails). For example, U.S. Pat. No. 5,437,870(Puritch et al.) discloses an ingestible molluscicide having a carrier(e.g., a bait), a simple iron compound, and ethylene diamine tetraceticacid (EDTA), salts of EDTA, hydroxyethlene triamine diacetic acid,(HEDTA) or salts of HEDTA. U.S. Pat. No. 6,352,706 of Puritch alsodiscloses an ingestible molluscicide containing a simple metal compound,an activity enhancing additive such as ethylene diamine disuccinic acid(EDDS) and derivatives thereof, and a carrier material edible tomolluscs. Australian Patent Application No. 77420/98 of Young alsodiscloses a stomach-action molluscicide that includes a metal complexone(i.e., iron EDTA) and a carrier.

The herbicidal (weed), algaecidal (algae) and fungicidal (plant disease)activity of metal chelates is also reported. For example, U.S. Pat. No.6,323,153 of Smiley teaches using various chelated calcium and magnesiumsalts to control the growth of various weeds in lawns. Smiley alsodiscloses, in U.S. Pat. No. 6,117,823, the use of aliphatic carboxylicacid diesters, such as dimethyl succinate and dimethyl glutarate, asnon-selective herbicides. Further examples include U.S. Pat. No.6,258,750 of Simpson, which teaches an algaecidal, herbicidal and/orfungicidal composition including a metal, the chelating agent ethylenediamine disuccinic acid (EDDS) or a salt thereof, and a source ofcalcium and chloride ions.

While the use of metal chelates and chelating agents in molluscicides,herbicides, algaecides, and fungicides is known, there is still a needfor an environmentally safe pesticidal formulation for controllinginsect pests.

SUMMARY OF THE INVENTION

The present invention is directed to an environmentally safe pesticidefor the control of insect pests. The pesticidal composition preferablyincludes two main components. The first component, which is preferablythe active ingredient, is a chelating agent, a metal complex of achelating agent, or mixtures thereof, and the second component is acarrier material. The carrier material can be a liquid or a solidcarrier, but it is preferably effective to promote ingestion and toattract specific targeted pests. The disclosed pesticidal compositionscan be used in dry or liquid form as baits. The composition can also beapplied to substrates or plants frequented by pests.

The present invention also provides a method for killing insect pestsusing a pesticidal composition having a first component, such as achelating agent, a metal complex of a chelating agent, or mixturesthereof, and a carrier material. The method includes the step ofapplying the pesticidal composition to an area infested with insectpests, such that the insect pests can ingest the pesticidal composition.The first component is preferably present at an amount that is effectiveto kill the insect pests upon ingestion.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides an environmentally compatible, pesticidalcomposition and method for the control of insect pests. In general, thecomposition includes two main components. The first component ispreferably a chelating agent, a metal complex of a chelating agent, ormixtures thereof, and the second component is a carrier material. Thecomposition is preferably used as an ingestible poison effective to killinsect pests.

Although the mode of action of chelators as insecticides is not known atthis time, it is possible that chelators disrupt critical processes ininsect pests by removing metal ion catalysts needed for enzyme systems.As well as cofactors for some enzyme systems, metals themselves playimportant roles in the digestive tracts of insect pests. Removal ofmetals by chelators could have serious consequences on insect pestmetabolism and physiology. As shown herein, chelating agents and theirmetal complexes represent novel, effective control agents for insectpests. Chelating agents and their metal complexes have proven to benon-toxic to humans and household animals, and have been usedextensively in the food, cosmetic and pharmaceutical industries.Although chelating agents and their metal complexes are documented inthe literature as effective control agents against molluscs and weeds,the use of ingestible chelating agents to combat insect pests has notheretofore been known. Unlike the rapid degradation observed with manynatural insecticides derived from plants, good stability is anticipatedwith dry formulations containing chelating agents, metal complexes of achelating agent, or mixtures thereof.

The first component of the pesticidal composition is the activeingredient which includes a chelating agent or its metal complex. Achelating agent is a substance whose molecules can form several bonds toa single metal ion, and thus, as a result, the chelating agent and ametal ion will form a metal chelate. The chelating agent can be added ina variety of forms. By way of non-limiting example, one or morechelating agents can be added as a salt. Preferably, in this embodiment,the chelating agent is added as a sodium salt, a potassium salt, acalcium salt, a zinc salt, an ammonium salt, an amine salt, an amidesalt, and combinations thereof.

Suitable chelating agents include, for example, aconitic acid, alaninediacetic acid (ADA), alkoyl ethylene diamine triacetic acids (e.g.,lauroyl ethylene diamine triacetic acids (LED3A)),aminotri(methylenephosphonic acid) (ATMP), asparticaciddiacetic acid(ASDA), asparticacidmonoacetic acid, diamino cyclohexane tetraaceticacid (CDTA), citraconic acid, citric acid, 1,2-diaminopropanetetraaceticacid (DPTA-OH), 1,3-diamino-2-propanoltetraacetic acid (DTPA),diethanolamine, diethanol glycine (DEG), diethylenetriaminepentaaceticacid (DTPA), diglycolic acid, dipicolinic acid (DPA),ethanolaminediacetic acid, ethanoldiglycine (EDG), ethionine,ethylenediamine (EDA), ethylenediaminediglutaric acid (EDDG),ethylenediaminedi(hydroxyphenylacetic acid (EDDHA),ethylenediaminedipropionic acid (EDDP), ethylenediaminedisuccinate(EDDS), ethylenediaminemonosuccinic acid (EDMS),ethylenediaminetetraacetic acid (EDTA),ethyleneglycolaminoethylestertetraacetic acid (EGTA), gallic acid,glucoheptonic acid, glutamicaciddiacetic acid (GLDA), glutaric acid,gluconic acid, glyceryliminodiacetic acid, glycinamidedisuccinic acid(GADS), glycoletherdiaminetetraacetic acid (GEDTA),2-hydroxyethyldiacetic acid, hydroxyethylenediaminetriacetic acid(HEDTA), hydroxyethyldiphosphonic acid (HEDP), hydroxyiminodiacetic acid(HIDA), iminodiacetic acid (IDA), iminodisuccinic acid (IDS), itaconicacid, lauroyl ethylene diamine triacetic acids (LED3A),methylglycinediacetate (MGDA), methyliminodiacetic acid (MIDA),monoethanolamine, nitrilotriacetic acid (NTA), nitrilotripropionic acid(NPA), saccharates, salicylic acid, serinediacetic acid (SDA), sorbicacid, succinic acid, tartaric acid, tartronic acid, triethanolamine,triethylenetetraamine, and combinations thereof. Preferably, thechelating agent is an aminopolycarboxylic acid, an amine, an amide, acarboxylic acid, a phosphonic acid and combinations thereof. Morepreferably, the chelating agent is EDTA, HEDTA, EDDS, HEDP, DTPA andcombinations thereof. Other suitable chelating agents capable ofcomplexing metal ions include, for example, amino acids, such asaspartic acid, glutamic acid, and lysine, as well as proteins, such aswhey powder, casein, and albumen.

As stated above, the first component can include the complex of achelating agent. Suitable metal complexes include, but are not limitedto, those containing Group I and II metals, and transition metals. Morepreferably, the metal complexes include aluminum ions, copper ions, ironions, manganese ions, nickel ions, zinc ions, and combinations thereof.These metal ions can be added in a variety of ionic states. The metalions can be added in a variety of forms. For example, metal ions can beadded to the composition as a metal salt which reacts with the chelatingagent to form a metal chelate. Preferably, when the metal ions are addedas a salt, they are added as, for example, a chloride salt, a sulfatesalt, a nitrate salt, a citrate salt, a phosphate salt, a carbonatesalt, an acetate salt, a hydroxide salt, a chelate salt, a sulfide salt,a sulfite salt, a succinate salt, a gluconate salt, a lactate salt, aformate salt, a nitrite salt, a salicylate salt, a carboxylic acid salt,and in combinations of these salts.

The composition of the invention typically includes a second componentwhich is a carrier material. A variety of materials can be used to formthe carrier material, including both liquid and solid carrier materials.In one embodiment, the carrier can be a food source that is effective topromote ingestion and/or attract specific target pests. Examples ofsuitable food sources for use in bait formulations include, but are notlimited to, wheat flour, wheat cereal, bran, molasses, vinegar, agar,gelatin, pet food, wheat, soy products, oats, corn, corn cob, vegetableoils, citrus mash, rice, fruits, fish by-products, sugars, coatedvegetable seeds, coated cereal seeds, dairy products, whey powder,casein, albumen, blood meal, bone meal, yeast, fats, beer products,paper fiber, cellulose, gelatin and mixtures thereof.

In an alternative embodiment, the carrier can be a liquid carrier thatis effective as a bait or that can leave a residue on the insect pest,which can lead to ingestion and subsequently death. For liquidformulations, water, alcohols, vinegar, plant-derived oils, mineraloils, glycerol, glycols, or combinations thereof can serve as thecarrier. The formulation can also include a food source, such as sugar,that can be mixed with the liquid carrier.

To enhance ingestion and attraction of pests, other suitable additivescan include but are not limited to attractants, phagostimulants, orcombinations thereof. These additives can be incorporated within thecomposition in a dry or liquid form. Non-food carriers can also be usedalone or combined with food materials or attractants that promoteingestion. Examples of non-food carriers suitable as additives includecellulose complexes, such as Biodac® (available from Kadant GranTekInc., Granger, Ind.), sand, clay, silica, polyacrylic acid polymers,polyacrylimide acid polymers, diatomaceous earth, alginate, and wax.

In addition to the first and second components, the pesticidalcomposition can optionally include other components, such as otherformulation enhancing additives. By way of non-limiting example, thecomposition can include preservatives, taste-altering additives,water-proofing agents, antioxidants, suspending agents, UV stabilizers,odor masking agents, and anti-microbial agents.

Suitable preservatives include Legend MK®, available from Rohm & HassCompany of Philadelphia, Pa. and CA-24, available from Dr. Lehmann andCo. of Memmingen/Allgäiu, Germany. Preservatives such as these cannormally be mixed with water to form a stock solution to be added to theformulation at a concentration in the range of about 10-750 ppm.

Waterproofing agents, which can also act as binders, can be added to thecomposition to improve the weatherability of the composition. These aretypically water insoluble compounds such as waxy materials and otherhydrocarbons. Examples of suitable waterproofing agents include paraffinwax, stearate salts, beeswax, and similar compounds.

Antioxidants can be useful additives for the composition in order toreduce the effect of oxidation. Examples of suitable antioxidantsinclude butylated hydroxytoluene (BHT), butylated hydroxy anisole (BHA)and natural antioxidants such as Vitamin E and ascorbic acid. UVprotectants include UV absorbers such as PABA and benzophenones, anddyes and fillers with UV absorbing properties.

Suspending agents may be added to improve the stability and shelf lifeof the composition. Examples of suitable suspending agents include gumarabic, guar gum, sodium caseinate, polyvinyl alcohol, magnesiumaluminum silicate (Van Gel B) from R.T. Vanderbilt Co. Inc., Norwalk,Conn., locust bean gum, xanthan gum, kelgum and mixtures thereof. Othersuitable thickeners include polyacrylic acid polymers such as Pemulenand Carbopol from BF Goodrich Corp., Brecksville, Ohio.

It may also be desirable to include within the composition tastealtering compounds that render the composition unpalatable to animals,such as humans and pets. Exemplary compositions include those having abitter taste. One such compound available commercially is BITREX® fromMcFarlane Smith Ltd. of Edinburgh, Scotland. These compounds aretypically added at a very low concentration. For example, a 0.1% BITREXsolution can be added to the composition at about 1% to 2% by weight ofthe total composition.

In use, the formulation of the pesticidal composition of the presentinvention can vary. Preferably, the composition is prepared as aready-to-use solution, a liquid concentrate, or a dry concentrate. Thecompositions can also be in the form of a liquid, solid, or semi-solidbait, or as a pre-treated strip or backing material covered with thecomposition in the dry form. For ingestion, chelators can be typicallyformulated as attractive baits. Alternatively, or in addition,formulations can be applied to the target insects whereby toxicquantities will be consumed from insect body surfaces via preening andgrooming behaviors.

To prepare a composition according to one embodiment of the presentinvention, a suitable amount of the first component, e.g., a metalchelate, a chelating agent, a salt of a chelating agent, and mixturesthereof, is blended in dry form with a carrier material. Thereafter,other ingredients, such as phagostimulants and waterproofing agents, canbe blended and mixed with the pesticidal composition.

In another embodiment, the composition can be prepared as a liquidformulation. The chelating agent is added first to an aqueous carrier,either as a salt or by combining the acid form of the chelating agentwith an appropriate base. A metal is then added in the form of a solublesalt and allowed to react with the chelating agent. Thereafter, otheringredients, such as phagostimulants and waterproofing agents, can beblended and mixed with the pesticidal composition.

The concentration of the chelating agent in the pesticidal compositionsof the present invention can vary. Preferably, the chelating agent ispresent at a concentration in the range of about 0.25% to about 40%, andmore preferably is present at a concentration in the range of about 0.5%to 30%. When formulated and presented in liquid form, chelating agentconcentrations typically range from 0.5% to 10%. Alternatively, liquidformulations can be applied to surfaces and allowed to dry. Evaporationof water during the drying process significantly increases theconcentration of chelating agent relative to other bait components, withtypical concentrations of chelating agents increasing to as high as 40%.

The pH of the pesticidal solution can also vary, but preferably, thepesticidal compositions of the present invention are effective over awide range of pH values. If necessary, the composition can includepH-adjusting additives. Suitable pH-adjusting additives include, forexample, calcium carbonate, potassium carbonate, hydrochloric acid,potassium hydroxide, ascorbic acid, tartaric acid, citric acid, andcombinations thereof. Such additives are preferably used at aconcentration in the range of about 0.05 to 5.0% by weight.

Since the composition is substantially nontoxic to humans or animals,the composition can be applied in domestic areas, including in andaround dwellings.

The pesticidal composition is effective against a wide range of insectpests including, but not limited to, aphids, leafhoppers, whitefly,sawfly larvae, caterpillars, beetles, cockroaches, earwigs, ants, flies,mosquitoes, wasps, and silverfish.

The following non-limiting examples serve to further illustrate thepresent invention.

EXAMPLE 1

Formulations containing sucrose and sodium EDTA were applied to glassmicroscope slides using an Eppendorf pipette (200 μL/rep). For freshtreatments, slides were allowed to dry overnight. For storagetreatments, slides were prepared 20 days previously and left uncoveredin the laboratory prior to use. Adult house flies (4 day old) wereanesthetized with CO₂ and transferred to 250 ml clear plastic cupscontaining a treated microscope slide, a small amount of granulatedsugar and a water reservoir. Cups were covered with fine netting securedwith rubber bands. Treatments consisted of 8 replicates of 5 insectpests each. Mortality was assessed 3 and 6 days after fly introduction.

TABLE 1 Mean % Mean % Storage Mortality Mortality Treatment Conditions 3Day 6 Day 1. 10% sodium EDTA 20 Days 47.5 92.5 (pH 8) + 25% sucrose 2.10% sodium EDTA 20 Days 40.0 80.0 (pH 10) + 25% sucrose 3. 1% sodiumEDTA 20 Days 20.0 35.0 (pH 10) + 25% sucrose 4. 25% sucrose 20 Days 2.52.5 5. 10% sodium EDTA Fresh 74.4 97.4 (pH 8) + 25% sucrose 6. 10%sodium EDTA Fresh 32.5 82.5 (pH 10) + 25% sucrose 7. 1% sodium EDTAFresh 40.0 72.5 (pH 10) + 25% sucrose 8. 25% sucrose Fresh 0.0 2.5 9.Untreated Fresh 0.0 0.0

Table 1 illustrates the mortality of adult house flies exposed totreatments and assessed after 3 and 6 days. High mortality of adulthouse flies was observed with 10% sodium EDTA baits prepared fresh orafter 20 days storage (Table 1). Some activity was also observed with 1%sodium EDTA formulations. Baits containing 10% sodium EDTA baits wereeffective at both pH 8 and pH 10.

EXAMPLE 2

Formulations containing sucrose and sodium EDTA were applied to glassmicroscope slides using an Eppendorf pipette (200 μL/rep). Adult houseflies (4 day old) were anesthetized with CO₂ and transferred (50 fliesper replicate) to cages (60×60×60 cm). Cages contained two treatedslides on the cage floor, a petri dish with a water reservoir and asugar cube. Treatments consisted of 1 replicate of 50 flies each.Mortality was assessed 4 and 6 days after fly introduction.

TABLE 2 Mean % Mean % Mortality Mortality Treatment 4 Day 6 Day 1. 10%sodium EDTA + 25% sucrose 42.0 100.0 2. Azamethiphos fly strips 36.066.8 3. Untreated 2.0 2.0

Table 2 illustrates the mortality of adult house flies exposed totreatments in cages and assessed after 4 and 6 days. After 6 days, highmortalities were observed with 10% sodium EDTA baits in a cage bioassay(Table 2). Sodium EDTA baits resulted in higher adult house flymortalities than commercially sold azamethiphos fly strips.

EXAMPLE 3

Formulations containing sucrose and sodium EDTA were applied to glassmicroscope slides using an Eppendorf pipette (200 μL/rep). Adult houseflies (5 day old) were anesthetized with CO₂ and transferred (50 fliesper replicate) to cages (60×60×60 cm). Cages contained two treatedslides on the cage floor, a petri dish with a water reservoir and asugar cube. Treatments consisted of 2 replicates (cages). Mortality wasassessed 2, 3 and 7 days after fly introduction.

TABLE 3 Mean % Mean % Mean % Mortality Mortality Mortality Treatment 2Day 3 Day 7 Day 1. 10% sodium EDTA + 25% sucrose 35.0 69.0 100.0 2.Azamethiphos fly strips 25.0 44.0 78.6 3. 25% sucrose 2.0 3.0 2.0

Table 3 illustrates the mortality of adult house flies exposed totreatments in cages and assessed after 2, 3 and 7 days. After 7 days,complete (100%) mortality of adult house flies was observed with a 10%sodium EDTA bait (Table 3). The chelator bait resulted in higher adulthouse fly mortalities than a commercially sold azamethiphos fly strip.

EXAMPLE 4

Formulations were applied to the center of glass microscope slides usingan Eppendorf pipette (200 μL/rep) and left uncovered in the laboratoryfor two weeks prior to testing. Small American cockroach nymphs from alaboratory colony were anesthetized with CO₂ and transferred to invertedpetri dishes containing a filter paper, a small amount of granulatedsugar and a water wick. Treatments consisted of 2 replicates of 3 insectpests each. Mortality was assessed 6 and 12 days following treatment.

TABLE 4 Mean % Mean % Mortality Mortality Treatment 6 Day 12 Day 1. 10%sodium EDTA + 25% sucrose 50.0 83.3 2. Untreated 16.7 16.7

Table 4 illustrates the mortality of small American cockroach nymphsexposed to treatments and assessed after 6 and 12 days. Sodium EDTAformulated with sucrose in a dried down layer resulted in moderatemortality of small American cockroach nymphs after 6 days and goodmortality after 12 days (Table 4).

EXAMPLE 5

Braided cotton rolls were saturated with treatments. Vinegar gnats froma laboratory colony were anesthetized with CO₂ and transferred toinverted petri dishes containing a filter paper, a small amount ofgranulated sugar and a water wick. Each dish also contained a treatedcotton roll. Treatments consisted of 8 replicates of 5 insect pestseach. Mortality was 5 days after fly introduction.

TABLE 5 Treatment Mean % Mortality 1. 10% sodium EDTA (pH 10) + 25%sucrose 7.5 2. 10% sodium EDTA (pH 8) + 25% sucrose 12.5 3. 1% sodiumEDTA (pH 10) + 25% sucrose 12.5 4. 10% sodium EDTA (pH 10) + 25%sucrose + 52.5 2.5% Brewer's Yeast 5. 10% sodium EDTA (pH 8) + 25%sucrose + 65.0 2.5% Brewer's Yeast 6. 1% sodium EDTA (pH 10) + 25%sucrose + 57.5 2.5% Brewer's Yeast 7. 10% sodium EDTA (pH 10) + 25%sucrose + 62.5 10% Brewer's Yeast 8. 10% sodium EDTA (pH 8) + 25%sucrose + 57.5 10% Brewer's Yeast 9. 1% sodium EDTA (pH 10) + 25%sucrose + 7.5 10% Brewer's Yeast 10. 25% sucrose 5.0 11. Untreated 8.1

Table 5 illustrates the mortality of adult vinegar gnats (Drosophilasp.) exposed to treatments and assessed after 5 days. Some activityagainst adult vinegar gnats (Drosophila sp.) was observed with sodiumEDTA formulations presented as liquids in saturated wicks (Table 5). Theaddition of brewer's yeast to sodium EDTA baits, significantly increasedadult vinegar gnat mortality.

EXAMPLE 6

Formulations were applied to the center of glass microscope slides usingan Eppendorf pipette (200 μL/rep) and they were allowed to dryovernight. Adult house flies (4 day old) were anesthetized with CO₂ andthen transferred to 4.2L Rubbermaid tubs with mesh lids containing atreated microscope slide, a petri dish containing a sugar cube, and awater reservoir. Treatments consisted of 4 replicates of 20 insect pestseach. Mortality was assessed 5 days after fly introduction.

Treatment Mean % Mortality 1. 7.5% Na₄EDTA (no food additives) 1.3 2.7.5% Na₄EDTA + 25% sucrose 63.8 3. Sucrose 0.0

Table 6 illustrates the mortality of adult house flies exposed totreatments and assessed after 5 days. Moderate mortality of adult houseflies was observed with sodium EDTA in a dried layer with 25% sucrose(Table 6). Poor activity was observed with sodium EDTA without foodadditives.

EXAMPLE 7

Formulations were applied to the center of glass microscope slides usingan Eppendorf pipette (200 μL/rep), and they were allowed to dryovernight. Adult house flies (3-5 day old) were anesthetized with CO₂and transferred to 4.2L Rubbermaid tubs with mesh lids containing onetreated microscope slide and a petri dish containing a sugar cube, and awater reservoir. Treatments consisted of 4 replicates of 20 insect pestseach. Mortality was assessed 4, 6 and 14 days after fly introduction.

TABLE 7 Mean % Mean % Mortality Mortality Treatment 4 days 6 days 1.7.5% Na₄EDTA 2.5 3.8 (no food additives) 2. 7.5% Na₄EDTA + Silwet L770.0 1.3 (no food additives) 3. 7.5% Na₄EDTA + 25% sucrose + 23.8 67.5Silwet L77 4. 7.5% Na₄EDTA + 25% sucrose 42.5 82.5 5. 25% Sucrose 0.01.3

Table 7 illustrates the mortality of adult house flies exposed totreatments and assessed after 4 and 6 days. Sodium EDTA formulationswith food additives were significantly more efficacious than sodium EDTAformulations without food additives against adult house flies,indicating that formulations are most effective as ingested toxins(Table 7). The formulation containing food additives and Silwet L77, asilicone glycol co-polymer surfactant, resulted in slower mortality thanthe formulation without Silwet L77.

EXAMPLE 8

Formulations were applied to the center of glass microscope slides usingan Eppendorf pipette (200 μL/rep), and they were allowed to dryovernight. Adult house flies (3 day old) were anesthetized with CO₂ andtransferred to 250 ml clear plastic cups containing a treated microscopeslide, a small amount of granulated sugar, and a water reservoir.Azamethiphos treatments consisted of two 4 cm strips (1 cm wide) placedon a glass slide for each replicate. Cups were covered with fine nettingsecured with rubber bands. Treatments consisted of 8 replicates of 5insect pests each. Mortality was assessed 1, 5 and 7 days after flyintroduction.

TABLE 8 Mean % Mean % Mean % Mortality Mortality Mortality Treatment¹ 1Day 5 Days 7 Days 1. 10% NaEDTA 2.5 72.5 87.5 2. FeEDTA 30.0 100.0 100.0(0.66% iron + 5% Na₄EDTA) 3. Ferrous gluconate 27.5 100.0 100.0 (0.66%iron) + 5% Na₄EDTA 4. Iron saccharate (iron sugar) 7.5 55.0 42.5 (0.66%iron) 5. Ferric sulfate (0.66% iron) 2.5 2.5 5.0 6. Ferrous sulfate(0.66% iron) 0.0 5.0 5.0 7. Ferric chloride (0.66% iron) 0.0 15.0 15.08. 25% sucrose 0.0 0.0 0.0 ¹All formulations contained sucrose.

Table 8 illustrates the mortality of adult house flies exposed totreatments and assessed after 1, 5 and 7 days. High adult house flymortalities were observed with sodium EDTA, iron EDTA and ferrousgluconate+sodium EDTA (Table 8). Some activity was also observed withiron saccharate (iron sugar). Poor activity was observed with simpleiron salts (ferric sulfate, ferrous sulfate, ferric chloride),indicating the unique activity of chelated iron.

EXAMPLE 9

Formulations were applied to the center of glass microscope slides usingan Eppendorf pipette (200 μL/rep ) and allowed to dry overnight. Adulthouse flies (6 day old) were anesthetized with CO₂ and transferred to4.2L Rubbermaid tubs with mesh lids. Each tub contained one treatedmicroscope slide, a petri dish containing a sugar cube and a waterreservoir. Treatments consisted of 4 replicates of 20 insect pests each.Mortality was assessed 1, 4 and 6 days after fly introduction.

TABLE 9 Mean % Mean % Mean % Mortality Mortality Mortality Treatment 1day 4 days 6 days 1. FeEDTA (0.66% iron + 55.0 71.3 90.0 5% NaEDTA) 2.Ferric chloride (0.66% iron) 3.8 13.8 16.3 3. NaEDTA (5% NaEDTA) 8.853.8 70.0 4. 25% Sucrose 0.0 1.3 1.3 ¹All formulations containedsucrose.

Table 9 illustrates the mortality of adult house flies exposed totreatments and assessed after 1, 4 and 6 days. High mortalities wereobserved with sodium EDTA and iron EDTA against adult house flies (Table9). Poor activity was observed with ferric chloride, a simple iron salt.

EXAMPLE 10

Formulations were applied to the center of glass microscope slides usingan Eppendorf pipette (200 μL/rep) and allowed to dry overnight. Adulthouse flies (4-5 day old) were anesthetized with CO₂ and transferred to250 ml clear plastic cups containing a treated microscope slide, a smallamount of granulated sugar and a water reservoir. Azamethiphostreatments consisted of two 4 cm strips (1 cm wide) placed on a glassslide for each replicate. Cups were covered with fine netting securedwith rubber bands. Treatments consisted of 8 replicates of 5 insectpests each. Mortality was assessed 1, 4 and 5 days after flyintroduction.

TABLE 10 Mean % Mean % Mean % Mortality Mortality Mortality Treatment 1Day 4 Day 5 Day 1. FeEDTA (0.66% iron + 70.0 100.0 100.0 5% Na₄EDTA) 2.FeHEDP (0.24% iron + 5.0 52.5 87.5 5% NaHEDP) 3. 10% Na₄EDTA 5.0 80.092.5 4. 5% Na₄EDTA 5.0 70.0 82.5 5. 10% NaHEDP 5.0 80.0 90.0 6. 5%NaHEDP 10.0 80.0 97.5 7. CuHEDP (0.8% copper + 2.5 50.0 52.5 5% NaHEDP)8. CuEDTA (0.8% copper + 0.0 37.5 45.0 5% NaEDTA) 9. 25% sucrose 0.0 0.00.0 ¹All formulations contained sucrose.

Table 10 illustrates the mortality of adult house flies exposed totreatments and assessed after 1, 4 and 5 days. High mortalities wereobserved with sodium HEDP, sodium EDTA, iron HEDP and iron EDTA againstadult house flies (Table 10). Some activity was also observed withcopper chelates of EDTA and HEDP.

EXAMPLE 11

Formulations were applied to the center of glass microscope slides usingan Eppendorf pipette (200 μL/rep) and allowed to dry overnight. Adulthouse flies (3-5 day old) were anesthetized with CO₂ and transferred to250 ml clear plastic cups containing a treated microscope slide, a smallamount of granulated sugar and a water reservoir. Azamethiphostreatments consisted of two 4 cm strips (1 cm wide) placed on a glassslide for each replicate. Cups were covered with fine netting securedwith rubber bands. Treatments consisted of 8 replicates of 5 insectpests each. Mortality was assessed 1, 5 and 7 days after flyintroduction.

TABLE 11 Mean % Mean % Mean % Mortality Mortality Mortality Treatment¹ 1Day 5 Days 7 Days 1. 10% NaEDTA 5.0 87.5 92.5 2. FeEDTA (5% NaEDTA +82.5 97.5 97.5 0.66% iron) 3. FeEDDS (5% NaEDDS + 55.0 62.5 70.0 0.74%iron) 4. 25% sucrose 0.0 0.0 2.5 ¹All formulations contained sucrose.

Table 11 illustrates the mortality of adult house flies exposed totreatments and assessed after 1, 5 and 7 days (I07-046). Highmortalities were observed with sodium EDTA and iron EDTA against adulthouse flies (Table 11). Some activity was also observed with iron EDDS.

The features and other details of the invention will now be moreparticularly described and pointed out in the claims. It will beunderstood that the particular embodiments of the invention are shown byway of illustration and not as limitations of the invention. Theprinciple features of this invention can be employed in variousembodiments without departing from the scope of the invention.

1. A method for killing insect pests, comprising: providing a pesticidalcomposition having a first component selected from the group consistingof a phosphonic acid chelating agent, a metal complex of the phosphonicacid chelating agent, a phosphonic acid chelating agent combined with ametal salt, and mixtures thereof, and a second component that comprisesa dry food source effective as a bait edible to insect pests; andapplying the pesticidal composition as a solid, dry form to an areainfested with insect pests, such that the insect pests can ingest thepesticidal composition.
 2. The method of claim 1, wherein the firstcomponent is present at an amount that is effective to kill the insectpests upon ingestion.
 3. The method of claim 1, wherein the firstcomponent is present in the composition at a concentration in the rangeof about 0.25% to 40%.
 4. The method of claim 1, wherein the firstcomponent is present in the composition at a concentration in the rangeof about 0.5% to 30%.
 5. The method of claim 1, wherein the phosphonicacid chelating agent is selected from the group consisting of phosphonicacid, its salts, and combinations thereof.
 6. The method of claim 5,wherein the phosphonic acid salt comprises a salt selected from thegroup consisting of a sodium salt, a potassium salt, a calcium salt, azinc salt, an ammonium salt, an amine salt, an amide salt, andcombinations thereof.
 7. The method of claim 1, wherein the phosphonicacid chelating agent is selected from the group consisting ofhydroxyethyl-diphosphonic acid (HEDP), aminotri(methylenephosphonicacid) (ATMP), salts of HEDP, salts of ATMP, and combinations thereof. 8.The method of claim 1, wherein the metal complex of the phosphonic acidchelating agent comprises a metal selected from the group consisting ofGroup IIa elements, transition metals, and combinations thereof.
 9. Themethod of claim 1, wherein the metal complex of the phosphonic acidchelating agent comprises a metal selected from the group consisting ofaluminum, copper, iron, manganese, nickel, zinc, ferric, iron, ferrousiron, and combinations thereof.
 10. The method of claim 1, wherein themetal complex of the phosphonic acid chelating agent further comprisesmetal ions in the form of a metal salt.
 11. The method of claim 10,wherein the metal salt comprises a salt selected from the groupconsisting of a chloride salt, an iron salt, a sulfate salt, a nitratesalt, a citrate salt, a phosphate salt, a carbonate salt, an acetatesalt, a hydroxide salt, a chelate salt, a sulfide salt, a sulfite salt,a succinate salt, a gluconate salt, a lactate salt, a formate salt, anitrite salt, a salicylate salt, a carboxylic acid salt, andcombinations thereof.
 12. The method of claim 1, wherein the carriermaterial is selected from the group consisting of wheat flour, wheatcereal, bran, molasses, vinegar, agar, gelatin, petfood, wheat, soyproducts, oats, corn, corn cob, vegetable oils, citrus mash, rice,fruits, fish by-products, sugars, coated vegetable seeds, coated cerealseeds, dairy products, whey powder, casein, albumen, blood meal, bonemeal, yeast, fats, beer products, and combinations thereof.
 13. Themethod of claim 1, wherein the carrier material further comprises atleast one additive selected from the group consisting of attractants,phagostimulants, cellulose complexes, sand, clay, silica, polyacrylicacid polymers, polyacrylimide acid polymers, diatomaceous earth,alginate, wax, and combinations thereof.
 14. A method for killing insectpests, comprising: providing an insecticidal composition having a firstcomponent that comprises a chelating agent formed from a phosphonicacid, the chelating agent being the only insecticidal component present,and a second component that comprises an ingestible carrier material;and applying the insecticidal composition to an area infested withinsect pests, such that the insect pests can ingest the insecticidalcomposition, wherein the first component is present at an amount that iseffective to kill the insect pests upon ingestion, and the carriermaterial is selected from the group consisting of water, sugars,alcohols, vinegar, plant-derived oils, mineral oils, glycerol, glycols,wheat flour, wheat cereal, bran, molasses, agar, gelatin, pet food,wheat, soy products, oats, corn, corn cob, vegetable oils, citrus mash,rice, fruits, fish by-products, coated vegetable seeds, coated cerealseeds, dairy products, whey powder, casein, albumen, blood meal, bonemeal, yeast, fats, beer products, attractants, phagostimulants,cellulose complexes, sand, clay, silica, polyacrylic acid polymers,polyacrylimide acid polymers, diatomaceous earth, alginate, wax, andcombinations thereof.
 15. The method of claim 14, wherein the firstcomponent is present in the composition at a concentration in the rangeof about 0.25% to 40%.
 16. The method of claim 14, wherein the firstcomponent is present in the composition at a concentration in the rangeof about 0.5% to 30%.
 17. The method of claim 14, wherein theinsecticidal composition further comprises a pH-adjusting agent.
 18. Themethod of claim 17, wherein the pH-adjusting agent is selected from thegroup consisting of calcium carbonate, potassium carbonate, hydrochloricacid, potassium hydroxide, ascorbic acid, tartic acid, citric acid, andcombinations thereof.
 19. The method of claim 17, wherein thepH-adjusting agent is present in the composition at a concentration inthe range of about 0.05 to 5.0% by weight.
 20. The method of claim 14,wherein the chelating agent is selected from the group consisting ofhydroxyethyl-diphosphonic acid (HEDP), aminotri(methylenephosphonicacid) (ATMP), salts of HEDP, salts of ATMP, and combinations thereof.21. The method of claim 14, wherein the chelating agent is complexedwith a transition metal to form a metal chelate.
 22. The method of claim21, wherein the metal complex of the chelating agent comprises thechelating agent combined metal ions in the form of a metal salt.
 23. Themethod of claim 21, wherein the metal chelate comprises a metal selectedfrom the group consisting of iron, aluminium, copper, manganese, nickel,zinc, and combinations thereof.
 24. The method of claim 14, wherein thecomposition is effective to kill pests selected from the groupconsisting of aphids, leafhoppers, whitefly, sawfly larvae,caterpillars, beetles, cockroaches, earwigs, ants, flies, mosquitoes,wasps, silverfish, and combinations thereof.